Thermogravimetric Study on Oxygen Adsorption/Desorption Properties of Double Perovskite Structure Oxides REBaCo2 O5+δ (RE = Pr, Gd, Y)

Abstract The oxygen adsorption/desorption properties of double perovskite structure oxides PrBaCo 2 O 5+δ , GdBa-Co 2 O 5+δ and YBaCo 2 O 5+δ were investigated by the thermogravimetry (TG) method in the temperature range of 400 ∼ 900 °C. The calculated oxygen adsorption/desorption surface reaction rate constants k a and k d of these double perovskite structure oxides were larger than the commonly used cubic perovskite oxides, such as Ba 0.95 Ca 0.05 Co 0.8 Fe 0.2 O 3-δ and Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ , whereas, the oxygen permeation flux was comparable to that of the latter, which was attributed to the smaller difference of oxygen vacancy in oxygen and nitrogen atmosphere (δδ/ V mol ) in these double perovskite structure oxides. The large oxygen adsorption/desorption rate constants of GdBaCo 2 O 5+δ and PrBaCo 2 O 5+δ made them nice catalyst coating materials, on other membrane surfaces, to improve the oxygen permeability.